District signal apparatus



(No Model.) 2 Sheets'Sheet 1.

- J. 0. WILSON.

DISTRIGT-SIGNAL APPARATUS. A I No. 290,302. Patented Dec. 18, 1883.

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(No Model.) 2 Sheets-Sheet 2.

J. 0. WILSON. 7. DISTRICT SIGNAL APPARATUS.

N0. 290.3021" A PatentedDec. 18, 1883.

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UNrTED STATES" PATENT Orrica.

JOHN CORNELIUS VILSON, OF BOSTON, MASSACHUSETTS.

DISTRICT SIGNAL APPARATUS.

SPECIFICATION forming part of Letters Patent No. 290,302, dated December 18, 1883.

Application filed September 8, 1883. No model.)

To rtZZ whom, it may concern.-

Be it known that I, JOHN C. WILson, of Boston, county of Suffolk, State of Massachusetts, have invented an Improvement in District Signal Apparatus, of which the following description, in connection with the accompanying drawings, is a specification, like letters on the drawings representing like parts.

My invention, relating to signal apparatus such as employed for fire alarm or districttelegraph purposes, has for its object to enable a return-signal to be transmitted from the main or central office to the boxes from which the signal was received, the said return-signal being entirely distinct from the other signals sent over the circuit, and being substantially unaffected by any current that can be applied to the line, except the one intended to operate it. The apparatus for transmitting the returnsignal is shown, in this instance, as an induction-coil and a key or transmitter by which the said induction-coil is normally retained wholly detached from the circuit, but which,

' when depressed, removes the battery from the .main circuit and connects it ina short circuit with the primary coil of the induction-coil, the said key or transmitter at the same time placing the secondary coil of the said induction-coil in the main circuit, so that pulsations or interruptions in the current of the battery-passing through the primary coil will produce, by induction, a series of impulses in the secondary coil and main circuit, which will operate a suitable receiving signal-instrument in the said main circuit at the signal-box.

Figure 1 shows, mainly in diagram, a sufficient portion of a circuit and signaling apparatus embodying this invention; Fig. 2, a plan view of the break-wheel of the signal-box, on a larger scale; Fig. 3, a diagram view of the apparatus at the main or central office, on a larger scale; and Fig. 4, a plan view of the break-wheel, showing its circuit-coi'inections with the main line and return-signaling device.

The main circuit over which the signals are transmitted from the signal-boxes A, any desired number of which may be included in the l a circuit, to the central station, 0, is shown in heavier lines than the branch circuits, which are brought into operation at the proper times to produce a returnsignal. The signal-box A includesv a break-wheel, a, which may be operated by any suitable or usual mechanism, which need not be shown and described, as numerous forms are well known. The said breakwheel is shown, in this instance, as forming a part of the main circuit, which is completed by a contact-spring, b, when resting on the unnotched portion of its periphery, and is interrupted when the notches in the said breakwheel pass under the end of the said spring I) in the usual manner. The spring 11 is connected by the portion 2 of the main circuit with a binding-screw, 3, which is connected by wire 4 with a contact-stop, 5, of the key or transmitter c at the central station, which has two front and two rear contact-points, the latter being normally in contact with two corresponding stops, the one, 5, of which stopsis thus connected through the said key with the wire 6, which passes to one pole of the battery B. The other pole of the said battery is connected by wire 7 with the contact-point ofthe key 0, which is normally in contact with the other rear contact stop or point, 8, for the said key, from which the circuit is continued by the wire 9 through a suitable receiving-instrument, R, which maybe any well-known form of receiver, preferably a self-starting register, and thence to the break-wheel a of the box at A, completing the main circuit.

The wires 4 and 6, at either side of the contact-point 5, are connected by branch Wires 10 and 12 with the terminals of the secondary coil of an induction-coil, d, which is thus normally shunted by the wires 4 and 6, when the key 0 is in its normal position in contact with the stops 5 and 7, but is brought into the main circuit by the depression of the key and consequent opening of the shunt at 5. When the key 0 is depressedto thus open the shunt 4 6 and introduce the secondary coil of the induction-coil d into the main circuit, the original main circuit will be broken at 8 between the wires 7 and 9, thus disconnecting the battery B therefrom. The circuit will, however, be completed by the branch wire 15 from the wire 6, connected with a front contact-stop, 16, for the key a, the corresponding point of which; is connected by wire-17 with the wire 9, so that when the key is depressed the main circuit is complete from the central station to the signal-box, but the battery B is removed from it, and the secondary coil of the induction-coil substituted therefor. One pole of the battery B is connected by wire 20, branching from the wire 7, with a contact-stop, 21, of the key 6, which contact-stop, when the said key is de pressed, is connected thereby with wire 22 and one terminal of the. primary coil of the indue tion-coil, the other terminal of which is connected by wire 23 with a vibrating armature, 0, which, when unattracted, is connected with its back stop, f, from which the circuit is continued by wire 24 to the other pole of the bat tery B, which is thus brought in circuit with the said primary coil by the depression of the key, and the said circuit is automatically broken and closed at c f, in the well-known manner, producing a rapid series of impulses of reverse polarity in the secondary coil and main circuit.

It will be understood that the operatorv at the central station depresses the key 0 imme diately after an intelligible signal is received by the instrument R, and the pulsatory current produced by the induction-coil in the main circuit will operate a signal, 71, at the box A, which will then be brought into the main circuit to receive the said signal, as follows: The said signal It is shown as of the kind in which the armature '1' polarized by a permanent magnet, is, is pivoted between the poles of an electro-magnet, m, and consequently vibrated by reversals in the polarity of the said magnet or of the current passing through it. The said magnet is included in a branch, 30, from the wire 2, connected with a spring, a, resting on the surface of the ,wheel a at the side of the spring b, which, with the wire 2, normally shunts the said wire 30 and signal-magnet m while the notched portions of the periphery of the wheel a are passing beneath the springs to give the signal. The notches by which the signal of the box is produced occupy only a portion of its periphery, and beyond the said portion the part opposite to the spring bis cut away, as shown at a, while that beneath the spring a remains entire, so that the said spring I) and portion of the wire 2 adjacent thereto are removed from the circuit, which will then pass from the wire 9 through the wheel a, spring a, and wire 30, to the wire 2 and binding-post 3 at the central station, thus bringing the signal-magnet m into the circuit, after the signal produced bythe wheel a has been wholly transmitted, and at the time when the central operator, having received the said signal, depresses the key cto give the return-signal at A. The said signal 71, when operated by the induction-coil (l in the proper manner, will give a rapidlyvibrating signal, which will be immediately understood as indicating that the message from the box has been properly received, and the said signal h will not operate except by arapidly-reversing pulsatory current, or, if affected at all by other currents, would only produce a single tap, which would be recognized as not being the proper return-signal, so that no mistake would be made.

It is obvious that the herein-described answering-signal is applicable to any kind of signal-box, either those in which the wheel a, is rotated by a motor that is wound up from time to time and tripped or released when each signal is sent, or in which the motor is wound for each signal, and, if desired, a multiple signal device might be employed-such as shown in Letters Patent granted to me September 4t, 1883, to which reference may be had-- in which case the periphery of the wheel a would be removed under both springs b and a, for a certain space, to permit the multiple device to operate.

For convenience in illustration, I have shown the ordinary well-known form of inductioncoil provided with an automatic circuit-breaker in circuit with its primary coil for producing electric impulses of reversed polarity. for operating the return-signal; but it is obvious that any apparatus for producing intermittent currents by induction may be employed as its equivalent, in connection with means for i11- terposing it in the circuit of the box and operating it at the proper time, without departing from this invention, the essential feature of which consists in operating the return-signal by impulses produced by induction, and consequently different in character from the battery-currents employed in transmitting the si gnals from the box to the central station.

I claim- 1. In a district signal apparatus, the signalbox or transmittingstation containing a signaling-instrument, and the main or signal-re ceiving station and main-line circuit connecting said stations, combined with the inductioncoil at the said main station, normally disconnected from the main circuit, and the circuit-changing device for introducing one of the coils of the said induction-coil into the main circuit, and connecting the battery and a circuit-breaker with the other coil of the said induction-coil, substantially as and for the purpose set forth.

2. The combination of a signal box or station containing a break-wheel and a polarized signaling-instrument with a central station in the same circuit, containing a battery normally included in the said circuit, an induction-coil normally removed from the said circuit, and a key or equivalent whereby the battery is removed from the circuit and included in one of the coils of the said induction-coil, and the other coil thereof is introduced into the circuit connecting the stations, substantially as described.

3. A signal box or station containing abreakwheel and a polarized signaling-instrument and device for interposing the latter in the circuit after the signal has been transmitted by the break-wheel, combined with an apparatus located at the station where the signal of the said break-wheel is received, for producing by induction electric impulses of reverse polarity, whereby the said signaling-instrument at the box is operated, substantially as described.

4. In a district signal apparatus, a main circuit connecting the boxes or signaling-stations with a central station, the said signaling boxes or stations including a signaling-instrun1ent and a break-wheel adapted to throw the said instrument into the circuit during a portion of its rotation, and the central station including an apparatus for producing electric-impulses by induction, and a key whereby the said apparatus may be connected with the main circuit, substantially as described.

5. The notched circuit-wheel aand contactsprings b and n co-operating therewith, combined with the signaling-instrument connected in a branch between the said springs, and the induction apparatus at the station where the signal produced by the said circuit-wheel is received for operating the said signaling-instrument, the said circuit-wheel having a portion of its periphery notched for its entire width and another portion of its periphery of full diameter where co-operating with one spring and of reduced diameter where co-operating with the other spring, substantially as described.

In testimonywhereofI have signed my name to this specification in the presence of two subscribing witnesses.

JOHN CORNELIUS YVILSON.

\Vitnesses:

Jos. P. LIVERMORE, W. H. SIGSTON. 

